1. Field of the Invention
The present invention relates to diaphragm flush valves for use in water closets and urinals and, more particularly, to a diaphragm disk for use in a diaphragm flush valve.
In particular the invention relates to improving the accuracy and stability of the flush valve. The diaphragm disk of the present invention is made out of composite material having a rubber layer over a portion of the disk making it less expensive than the prior art rubber-coated brass disks. The diaphragm disk of the present invention also includes a plurality of short and rounded extensions circumferentially spaced around the disk making it more accurately and stably centered on the diaphragm.
2. Description of Related Art
Flush valves in water closets, urinals, and other plumbing devices which utilize a flexible diaphragm to establish and to seal off the connection between the inlet and outlet are well-known in the art. Typically, these flush valves have diaphragm assemblies that include diaphragm disks. The purpose of such disks is two-fold; namely to provide for the assembly of diaphragm components without the necessity of adhesive by securing a diaphragm to a guide member; and to provide a seal between the disk and a relief valve and between the disk and the diaphragm.
Diaphragm disks of the prior art use brass threads to secure the diaphragm to the guide member. The use of brass for the diaphragm disk increases the weight of the disk as well as the manufacturing costs.
A typical prior art diaphragm flush valve assembly is shown in FIG. 1 of U.S. Pat. No. 5,232,194 to Saadi et al. and is incorporated herein by reference.